<?php
/**
 * Akeeba Engine
 * The modular PHP5 site backup engine
 * @copyright Copyright (c)2009-2012 Nicholas K. Dionysopoulos
 * @license GNU GPL version 3 or, at your option, any later version
 * @package akeebaengine
 *
 */

// Protection against direct access
defined('AKEEBAENGINE') or die();

class AEPostprocS3 extends AEAbstractPostproc
{
	public $cache = null;
	
	public function __construct()
	{
		parent::__construct();
		
		$this->can_delete = true;
		$this->can_download_to_browser = true;
		$this->can_download_to_file = true;
	}
	
	public function processPart($absolute_filename)
	{
		// Retrieve engine configuration data
		$config = AEFactory::getConfiguration();

		$accesskey	= trim( $config->get('engine.postproc.s3.accesskey', '') );
		$secret		= trim( $config->get('engine.postproc.s3.secretkey', '') );
		$usessl		= $config->get('engine.postproc.s3.usessl', 0) == 0 ? false : true;
		$bucket		= $config->get('engine.postproc.s3.bucket', '');
		$legacy		= $config->get('engine.postproc.s3.legacy', 0);
		$directory	= $config->get('volatile.postproc.directory', null);
		$lowercase	= $config->get('engine.postproc.s3.lowercase', 1);
		$rrs		= $config->get('engine.postproc.s3.rrs', 1);
		if(empty($directory)) $directory	= $config->get('engine.postproc.s3.directory', 0);

		// Sanity checks
		if(empty($accesskey))
		{
			$this->setError('You have not set up your Amazon S3 Access Key');
			return false;
		}

		if(empty($secret))
		{
			$this->setError('You have not set up your Amazon S3 Secret Key');
			return false;
		}

		if(empty($bucket))
		{
			$this->setError('You have not set up your Amazon S3 Bucket');
			return false;
		} else {
			// Remove any slashes from the bucket
			$bucket = str_replace('/', '', $bucket);
			if($lowercase) {
				$bucket = strtolower($bucket);
			}
		}
		
		// Create an S3 instance with the required credentials
		$s3 = AEUtilAmazons3::getInstance($accesskey, $secret, $usessl);
		
		// Do not use multipart uploads when in an immediate post-processing step,
		// i.e. we are uploading a part right after its creation
		$immediateEnabled = $config->get('engine.postproc.common.after_part', 0);
		if($immediateEnabled) {
			$noMultipart = true;
		} else {
			$noMultipart = false;
		}
		
		// Disable multipart uploads if the user requested it
		if($legacy) {
			$noMultipart = true;
		}
		
		// Are we already processing a multipart upload?
		if(!empty($this->cache))
		{
			// Continue processing an existing file and return
			$filename = $this->cache->filename;
			$absolute_filename = $this->cache->absolute_filename;
			$partNumber = $this->cache->partnumber;
			$uploadID =	$this->cache->uploadid;
			$etags = $this->cache->etags;
			
			$partNumber++;
			
			AEUtilLogger::WriteLog(_AE_LOG_DEBUG,"S3 -- Uploading part $partNumber of $uploadID");

			// DEBUG
			/**
			$flatetags = implode(', ',$etags);
			AEUtilLogger::WriteLog(_AE_LOG_DEBUG,"S3 -- Absolute/relative filenames: $absolute_filename ### $filename");
			AEUtilLogger::WriteLog(_AE_LOG_DEBUG,"S3 -- Etags: ".$flatetags);
			AEUtilLogger::WriteLog(_AE_LOG_DEBUG,"S3 -- Serialized cache: ".serialize($this->cache));
			/**/
			
			$fileInfo = AEUtilAmazons3::inputFile( $absolute_filename, false );
			$fileInfo['UploadID'] = $uploadID;
			$fileInfo['etags'] = $etags;
			$fileInfo['PartNumber'] = $partNumber;
			$input = $fileInfo; // So that it doesn't get overwritten
			$etag = AEUtilAmazons3::uploadMultipart($input, $bucket, $filename);
			
			if($etag === 0) {
				// Done uploading, finalize
				$this->cache = null;
				AEUtilLogger::WriteLog(_AE_LOG_DEBUG, "S3 -- Finalizing multipart upload of ".basename($absolute_filename)." (part #$partNumber)");
				$result = AEUtilAmazonS3::finalizeMultipart($fileInfo, $bucket, $filename);
				$this->propagateFromObject($s3);
				if($result === false) {
					// Finalization failed
					return false;
				} else {
					// Finalization successful
					return true;
				}
			} elseif($etag === false) {
				// Upload failed 
				$this->propagateFromObject($s3);
				return false;
			} else {
				// Successfully uploaded part
				$this->propagateFromObject($s3);
				$fileInfo['etags'][] = $etag;
				// Update stored values
				$this->cache->partnumber = $partNumber;
				$this->cache->etags = $fileInfo['etags'];
				$this->cache->uploadid = $fileInfo['UploadID'];
				// Return -1 so that we get called again
				return -1;
			}
		}
		
		// If we are here, we'll have to start uploading the file. Let's prepare ourselves for that.
		// Fix the directory name, if required
		if(!empty($directory))
		{
			$directory = trim($directory);
			$directory = ltrim( AEUtilFilesystem::TranslateWinPath( $directory ) ,'/');
		}
		else
		{
			$directory = '';
		}
		
		// Parse tags
		$directory = AEUtilFilesystem::replace_archive_name_variables($directory);
		$config->set('volatile.postproc.directory', $directory);

		// Calculate relative remote filename
		$filename = basename($absolute_filename);
		if( !empty($directory) && ($directory != '/') ) $filename = $directory . '/' . $filename;
		
		// Store the absolute remote path in the class property
		$this->remote_path = $filename;

		// Do we have to upload in one go or do a multipart upload instead?
		$filesize = @filesize($absolute_filename);
		if( ($filesize > 5242880) && !$noMultipart )
		{
			AEUtilLogger::WriteLog(_AE_LOG_DEBUG, "S3 -- Starting multipart upload of ".basename($absolute_filename));
			// Start multipart processing for files over 5Mb
			$fileInfo = AEUtilAmazons3::inputFile( $absolute_filename, false );
			$input = $fileInfo; // Required to avoid the original array being tampered with
			$uploadID = AEUtilAmazonS3::startMultipart(
				$input,
				$bucket,
				$filename,
				AEUtilAmazons3::ACL_BUCKET_OWNER_FULL_CONTROL,	// ACL (bucket owner has full control, file owner gets full control)
				array(),										// Meta headers
				// Other request headers
				array(
					// Amazon storage class (support for RRS - Reduced Redundancy Storage)
					'x-amz-storage-class'	=> $rrs ? 'REDUCED_REDUNDANCY' : 'STANDARD'
				)
			);
			
			// Necessary warnings propagation, no matter the outcome
			$this->propagateFromObject( $s3 );
			
			if($uploadID === false) {
				// We couldn't start the upload. Bail out at once!
				return false;
			} else {
				// Save the information we need for multipart uploading
				$fileInfo['UploadID'] = $uploadID;
				$fileInfo['etags'] = array();
				
				$cache = array(
					'absolute_filename'		=> $absolute_filename,
					'filename'				=> $filename,
					'partnumber'			=> 0,
					'uploadid'				=> $uploadID,
					'etags'					=> array()
				);
				
				$this->cache = (object)$cache;
				
				// Return -1 so that we get called again, even on the same step
				return -1;
			}
		}
		else
		{
			AEUtilLogger::WriteLog(_AE_LOG_DEBUG, "S3 -- Legacy (single part) upload of ".basename($absolute_filename));
			// Legacy single part uploads
			$result = $s3->putObject(
				AEUtilAmazons3::inputFile( $absolute_filename, false ),		// File to read from
				$bucket,													// Bucket name
				$filename,													// Remote relative filename, including directory
				AEUtilAmazons3::ACL_BUCKET_OWNER_FULL_CONTROL,				// ACL (bucket owner has full control, file owner gets full control)
				array(),													// Meta headers
				// Other request headers
				array(
					// Amazon storage class (support for RRS - Reduced Redundancy Storage)
					'x-amz-storage-class'	=> $rrs ? 'REDUCED_REDUNDANCY' : 'STANDARD'
				)
			);
	
			// Return the result
			$this->propagateFromObject( $s3 );
			return $result;
			
		}
	}
	
	/**
	 * Implements object deletion
	 * 
	 * @see backend/akeeba/abstract/AEAbstractPostproc#delete($path)
	 */
	public function delete($path)
	{
		// Retrieve engine configuration data
		$config = AEFactory::getConfiguration();

		$accesskey	= trim( $config->get('engine.postproc.s3.accesskey', '') );
		$secret		= trim( $config->get('engine.postproc.s3.secretkey', '') );
		$usessl		= $config->get('engine.postproc.s3.usessl', 0) == 0 ? false : true;
		$bucket		= $config->get('engine.postproc.s3.bucket', '');
		$lowercase	= $config->get('engine.postproc.s3.lowercase', 1);
		
		// Sanity checks
		if(empty($accesskey))
		{
			$this->setError('You have not set up your Amazon S3 Access Key');
			return false;
		}

		if(empty($secret))
		{
			$this->setError('You have not set up your Amazon S3 Secret Key');
			return false;
		}

		if(empty($bucket))
		{
			$this->setError('You have not set up your Amazon S3 Bucket');
			return false;
		} else {
			// Remove any slashes from the bucket
			$bucket = str_replace('/', '', $bucket);
			if($lowercase) {
				$bucket = strtolower($bucket);
			}
		}
		
		// Create an S3 instance with the required credentials
		$s3 = AEUtilAmazons3::getInstance($accesskey, $secret, $usessl);

		// Delete the file
		$result = $s3->deleteObject( $bucket, $path );
		
		// Return the result
		$this->propagateFromObject( $s3 );
		return $result;
	}
	
	public function downloadToFile($remotePath, $localFile, $fromOffset = null, $length = null)
	{
		// Retrieve engine configuration data
		$config = AEFactory::getConfiguration();

		$accesskey	= trim( $config->get('engine.postproc.s3.accesskey', '') );
		$secret		= trim( $config->get('engine.postproc.s3.secretkey', '') );
		$usessl		= $config->get('engine.postproc.s3.usessl', 0) == 0 ? false : true;
		$bucket		= $config->get('engine.postproc.s3.bucket', '');
		$lowercase	= $config->get('engine.postproc.s3.lowercase', 1);
		$rrs		= $config->get('engine.postproc.s3.rrs', 1);
		
		// Sanity checks
		if(empty($accesskey))
		{
			$this->setError('You have not set up your Amazon S3 Access Key');
			return false;
		}

		if(empty($secret))
		{
			$this->setError('You have not set up your Amazon S3 Secret Key');
			return false;
		}

		if(empty($bucket))
		{
			$this->setError('You have not set up your Amazon S3 Bucket');
			return false;
		} else {
			// Remove any slashes from the bucket
			$bucket = str_replace('/', '', $bucket);
			if($lowercase) {
				$bucket = strtolower($bucket);
			}
		}
		
		// Create an S3 instance with the required credentials
		$s3 = AEUtilAmazons3::getInstance($accesskey, $secret, $usessl);
		
		if($fromOffset && $length) {
			$toOffset = $fromOffset + $length - 1;
		} else {
			$toOffset = null;
		}
		$result = $s3->getObject($bucket, $remotePath, $localFile, $fromOffset, $toOffset);
		
		// Return the result
		$this->propagateFromObject( $s3 );
		return $result;
	}
	
	public function downloadToBrowser($remotePath)
	{
		// Retrieve engine configuration data
		$config = AEFactory::getConfiguration();

		$accesskey	= trim( $config->get('engine.postproc.s3.accesskey', '') );
		$secret		= trim( $config->get('engine.postproc.s3.secretkey', '') );
		$usessl		= $config->get('engine.postproc.s3.usessl', 0) == 0 ? false : true;
		$bucket		= $config->get('engine.postproc.s3.bucket', '');
		$lowercase	= $config->get('engine.postproc.s3.lowercase', 1);
		$rrs		= $config->get('engine.postproc.s3.rrs', 1);

		// Sanity checks
		if(empty($accesskey))
		{
			$this->setError('You have not set up your Amazon S3 Access Key');
			return false;
		}

		if(empty($secret))
		{
			$this->setError('You have not set up your Amazon S3 Secret Key');
			return false;
		}

		if(empty($bucket))
		{
			$this->setError('You have not set up your Amazon S3 Bucket');
			return false;
		} else {
			// Remove any slashes from the bucket
			$bucket = str_replace('/', '', $bucket);
			if($lowercase) {
				$bucket = strtolower($bucket);
			}
		}
		
		// Create an S3 instance with the required credentials
		$s3 = AEUtilAmazons3::getInstance($accesskey, $secret, $usessl);
		
		$expires = time() + 10; // Should be plenty of time for a simple redirection!
		$stringToSign = "GET\n\n\n$expires\n/$bucket/$remotePath";
		$signature = AEUtilAmazons3::__getHash($stringToSign);
		
		$url = $usessl ? 'https://' : 'http://';
		$url .= "$bucket.s3.amazonaws.com/$remotePath?AWSAccessKeyId=".urlencode($accesskey)."&Expires=$expires&Signature=".urlencode($signature);
		
		return $url;
	}
}